The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 14, 1993
Filed:
Mar. 20, 1990
Tadayoshi Saito, Hitachiohta, JP;
Kohji Tachibana, Katsuta, JP;
Susumu Takahashi, Ibarakimachi, JP;
Nobuyuki Yokokawa, Mito, JP;
Masahide Nomura, Hitachi, JP;
Hiroshi Matsumoto, Ibaraki, JP;
Makoto Shimoda, Katsuta, JP;
Hisanori Miyagaki, Hitachiohta, JP;
Eiji Tohyama, Ibaraki, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A process control apparatus and a process control system for observing the waveform of the deviation between a set point which controls the process in a control loop and the process controlled variable transmitted from the process so that the operating parameters are adjusted in accordance with a predetermined adjustment rule by using the deviation based upon the absolute value of a wave for every half cycle of the wave. Therefore, even if the process controlled variable is influenced, the area of the wave cannot be changed significantly. As a result, the operating parameters can be adjusted correctly, causing the process controlled variable to quickly coincide with the set point.